In the latest firefox, I found that, when you try to use the following code in web console:
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
[10:33:00.787] Use of enablePrivilege is deprecated.
Please use code that runs with the system principal (e.g. an extension) instead.
For the firefox 3.6, I always use this way to simply test some of my XPCOM components, it's very convenient. But in the latest firefox, I found that i cannot be used anymore.
So If currently I have written a C++ XPCOM component, is there a simple way that I can try to test it besides having to write and register another test component?
Of course, any suggestion is very appreciated.
Binary (C++) XPCOM usage is very heavily discouraged (or to put it more firmly, DEAD DEAD DEAD) in recent Firefox builds:
http://adblockplus.org/blog/binary-xpcom-components-are-dead-js-ctypes-is-the-way-to-go
http://starkravingfinkle.org/blog/2011/07/add-ons-binary-components-and-js-ctypes/
http://hackademix.net/2011/07/14/killing-binary-xpcom-in-add-ons-is-javascript-fit/
MDN specifies alternatives for getting binary XPCOM components, although I don't know if any are an improvement for your scenario:
https://developer.mozilla.org/En/Firefox_addons_developer_guide/Using_XPCOM—Implementing_advanced_processes
Formerly binary components should now use js-ctypes:
https://developer.mozilla.org/en/js-ctypes
Related
I am working on writing a Frama-C plug-in and I would like to know if it is possible to get the weakest precondition of something using WP from within my plug-in, and if so, how exactly? In the past I've used Db.Value, for example, to use the results of the EVA plug-in in my own plug-in. Is there something similar to Db.Value for WP?
The WP plugin exposes its API in the WP.mli file, that is generated by collecting the interfaces of the higher-level modules composing Wp. you can find it in src/plugins/wp/Wp.mli.
However, you should be aware that this API should not be considered stable, and non-backward compatible changes may be introduced in newer Frama-C versions.
I am starting to work on a browser extension and because of the nature of the extension I need to develop it in C++. I am currently working with Firefox but would like my code to be portable across browsers. First of all is there a library or an interface (like the NPAPI) that I can use to ensure this for extensions? What are the things I need to worry about?
I am not using XPCOM and instead writing the functionality in C++ so that I can just compile the library for each platform and can bundle it with the extension for each browser. For Firefox, I am using XUL to develop the JS wrapper for my extension and an IDL file generates the c++ interface for me. Can I do something better? I just want to make sure I am not going down the wrong path.
EDIT: Please also suggest if there is a better forum for this type of question.
My background: a few years back, I worked on a cross-platform, cross-browser NPAPI plugin that used OpenGL to do image rendering. I've paid some attention to the space since then, but it's not what I do nowadays. I've written non-plugin extensions for Firefox but not Safari or Chrome.
A lot depends on exactly what you want your extension to do, and what sort of user interface you want to present. Different browsers have different ideas of what extensions may and may not do.
If you just wanted to display images or video in a custom format, NPAPI is probably your best bet. NPAPI is fundamentally a thin wrapper around native platform APIs. As such, cross-platform NPAPI code has to deal with individual platform quirks, as well as different levels of support for NPAPI from browsers. Google has a project called Pepper to fix some of NPAPI's issues, but Pepper doesn't yet have support from any browser besides Chrome.
Google's Native Client project provides an alternative to NPAPI for running native code, but it imposes restrictions on native code. For example, pthreads are allowed, but network access isn't. There is a NaCL subproject called c_salt which appears to address the sort of HTML/JS UI + native code integration you seek. Unfortunately it's still in the design phase, and thus isn't terribly helpful for writing extensions today.
My understanding is that, for now, a cross-browser extension which integrates with the browser UI and also integrates with native code is not feasible. Safari and Chrome both restrict extensions much more than Firefox does, and only allow extensions written in JavaScript. I don't know if it's possible to have an extension in Safari or Chrome interact with a browser plugin written in NPAPI. I'm guessing it's either impossible or incredibly painful.
Overall, you'll find life much, much easier if you carefully restrict which browsers and platforms to target. Exactly which browsers and platforms to choose is something that only you can decide.
Not many know about it, but yes, you can write cross browser plugins using Qt. :-)
You can use the QtBrowserPlugin just for that.
The QtBrowserPlugin solution makes it
easy to write browser plugins that can
be used in Mozilla FireFox, Safari,
Opera, Google Chrome, QtWebKit and any
other web browser that supports the
"Netscape Plugin API", NPAPI.
QtBrowserPlugin is part of the Qt Solutions packages.
I'm thinking of creating an application that can use Firefox as a download manager. Is there any way to control Firefox (add downloads, start/stop downloads, etc) from an external program in C/C++?
If that is not possible, then perhaps an extension that can do that? If an extension is the only way, then how do I communicate with the extension from outside of Firefox?
You're starting with a solution, not a problem. The easier idea is to use XulRunner, the platform on which FireFox is built. You'd effectively implement your own application as a XulRunner plugin and use Necko (the network layer of XulRunner and FireFox) from there.
First of all I suggest that you familiarize yourself with developer.mozilla.org
As far as I understand, most Mozilla platform functions are available through a cross language API known as XPCOM. There's also a plugin API but it's primary aim is to visualize stuff (used by Flash, etc.).
Take a look at Gecko API. It allows third party developers to use the same technology as found in Mozilla.
For downloading files no need to use Firefox. Consider using libcurl.
Take a look at wget.
I wrote a program in C++/OpenGL (using Dev-C++ compiler) for my calculus 2 class. The teacher liked the program and he requested me to somehow put it online so that instead of downloading the .exe I can just run it on the web browser. Kinda like java applets run on the browser.
The question is:
How if possible, can I display a C++/OpenGL program in a web browser?
I am thinking of moving to JOGL which is a java interpretation of OpenGL but I rather stay in C++ since I am more familiar with it.
Also is there any other better and easier 3D web base API that I can consider?
There is a lot activity recently with WebGL. It is a binding for Javascript to native OpenGL ES 2.0 implementations, designed as an extension of the canvas HTML5 element.
It is supported by the nightly builds of Firefox, Safari, Chrome and Opera.
Have a look at these tutorials, based on the well known NeHe OpenGL tutorials.
Several projects based on WebGL are emerging, most notably Scenegraphs APIs.
From Indie teams: SceneJS, GLGE, SpiderGL.
From Google: the team behind O3D plugin is trying to implement a pure WebGL backend (source) for the project, so that no plugin will be necessary.
From W3C/Web3D: There is an ongoing discussion to include X3D as part of any HTML5 DOM tree, much like SVG in HTML4. The X3DOM project was born last year to support this idea. Now it is using WebGL as its render backend, and is version 1.0 since March 2010.
I'm almost sure that WebGL is the way to go in the near future. Mozilla/Google/Apple/Opera are promoting it, and if the technology works and there is sufficient customer/developer demand, maybe Microsoft will implement it on IE (let's hope that there will be no "WebDX"!).
AFAIK, there's only 3 options:
Java. it includes the whole OpenGL stack.
Google's Native Client (NaCL), essentially it's a plugin that let's you run executable x86 code. Just compile it and call it from HTML. Highly experimental, and nobody will have it already installed. Not sure if it gives you access to OpenGL libraries.
Canvas:3D. Another very experimental project. This is an accelerated 3D API accessible from JavaScript. AFAICT, it's only on experimental builds of Firefox.
I'd go for Java, if at all.
OTOH, if it's mostly vectorial works (without lots of textures and illumination/shadows), you might make it work on SVG simply by projecting your vectors from 3D to 2D. In that case, you can achieve cross-browser compatibility using SVGWeb, it's a simple JavaScript library that allows you to transparently use either the browser's native SVG support or a Flash-based SVG renderer.
Do you really have the time to rewrite it? I thought students were meant to be too busy for non-essential assignment work.
But if you really want to do it, perhaps a preview of it running as a flash movie is the easiest way. Then it's just a matter of doing that and you could provide a download link to the real application if people are interested.
Outside of Java, in-browser OpenGL is really in its infancy. Google's launched a really cool API and plugin for it though. It's called O3D:
http://code.google.com/apis/o3d/
Article about the overall initiative:
http://www.macworld.com/article/142079/2009/08/webgl.html
It's not OpenGL, but the Web3D Consortium's X3D specification may be of interest.
Another solution is to use Emscripten (a source-to-source compiler).
Emscripten supports C/C++ and OpenGL and will translate the source into html/JavaScript.
To use Emscripten you will need to use SDL as a platform abstraction layer (for getting an OpenGL context as well as loading images).
Emscripten is currently being used in Unreal Engine and will also be used in the Unity 5 engine.
Read more about the project here:
https://github.com/kripken/emscripten
Two approaches:
Switch to Java. However, your application will suffer from a loss of performance as a trade off for portability. But since Java is everywhere, this approach ensures that your code can be executed in most browsers.
Use ActiveX, which allows you to run native binary code for Microsoft Windows. This is not recommended in production because activeX is well known as a potential security hole, but since your lecturer is the one viewing it, security doesn't seem to be a big deal. This is applicable for Microsoft platform (Windows+IE) only.
Is there any browser I could embedd in C++ application on Windows?
I need all features typical browser has (HTTP client, cookies support, DOM style HTML parser, JavaScript engine) except rendering.
Because I don't need rendering capability (and that's rather big part of a browser) I would prefer a browser with non monolithic design so I wouldn't have to include rendering stuff into my project.
It would be nice if it had C++ rather than C API.
I need this embedded browser mainly because I have much trouble finding C++ HTML parser which could handle broken HTML like browsers do.
If you know any, please answer Library Recommendation: C++ HTML Parser SO question or at least vote on it to increase a chance someone will give a good answer.
Sounds like all you need is something like libcurl which is an HTTP library and will let you do GET/POST/etc.
When I think browser I generally think rendering/JavaScript and not HTTP library.
Edit
In that case I'd look at WebKit (which I think has a C++ API) and hope you don't have to pull too much in.
Edit Again
On second thought (since rendering is such a big part of what browsers do), you might be better off using a stand-alone JS engine like SpiderMonkey and a stand-alone XML parser like Xerces-C (plus maybe tidy to make your HTML into XML).
I'm a bit confused by your question regarding embedding a web browser for which you don't need rendering capabilities. A web browser is rendering web pages by definition, unless you just need HTTP and XML with JavaScript capabilities which is a subset of a browser functionalities?
If you need a web browser to embed in your C++ application, I would suggest to consider Qt that comes with the WebKit plugin. It is C++, LGPL and has a very nice IDE (Qt Creator). I tried Qt with Qt Creator on unix (Ubuntu) and it was very impressive. The debugger is a bit light but it is just the first version. The adapter of Qt into visual c++ 2008 is now free.
You might also want to check out Awesomium-- it's free for non-commercial use and has all of the features you're looking for (if you don't need rendering, simply don't use it).
There is a project called CEF = The Chromium Embedded Framework - it is:
a simple framework for
embedding Chromium-based browsers in other applications. It is a
BSD-licensed open source project founded by Marshall Greenblatt in
2008 and based on the Google Chromium project. Unlike the Chromium
project itself, which focuses mainly on Google Chrome application
development, CEF focuses on facilitating embedded browser use cases in
third-party applications.
and yes:
The base CEF framework includes support for the C and C++ programming
languages.
Including javascript support and html parsing makes this non-trivial task - you have to use one of the available browsers.
IE is usable through its COM model - you can create instance of it in your window be it invisible or not and call its javascript/html capabilities.
It has been designed to be used like that since the beginning and certainly it is working fine.
The other options are:
Gecko/Mozilla - a couple of years ago it wasn't usable like this, currently I think it is.
WebKit/V8 - no public API has been released for chrome yet, you could use webkit itself, but it doesn't have javascript engine. Another option is to take a look at the Chrome codebase and see if you could get out of it what you need.
I would probably go for IE, since it is maybe the easiest option and I have already used it. The other options seem to me more like building a browser instead of just using it.
How about Gecko ? You may not need the entire engine but you may find some its components useful like SpiderMonkey which is a JavaScript engine written in C.
I'd recommend picking up Qt for C++ programming. It has a built-in library that embeds Webkit with all the bells'n'whistles, and Qt is a great C++ library in general.
Old question, I know, but take a look on
http://msdn.microsoft.com/en-us/library/ky29ffxd%28v=vs.94%29.aspx
IActiveScript and family COM interfaces allows script execution (not only JS, any language that registers as script interpeter, for that matter) in-memory.